Taking many features from pro-level equipment, this 2-piece cap-free design Tiagra chainset offers unbeatable performance 2-piece cap-free design is quick & easy to install whilst being lighter & stiffer than a traditional crank/ bottom bracket assembly SG-X chainrings feature strategically placed chain pick-up pins & tooth profiles to ensure fast & positive shifting Designed to work with Hollow Tech II type bottom bracket cups Compatible with 10-speed HG-X chains Anodized aluminium crank arms Lightweight aluminium chainrings 4 arm, 110 mm bolt circle diameter